Monkey-wrench



s. H. BELLOWSQ Monkey-Wrench.

- No. 228,437. Patented June 8,1880.

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PErifis, PHOTO-LITHOGRAFNER, WASHINGTON n c UNTTED STATES STEPHEN H.BELLOWS, OF ATHOL, MASSACHUSETTS.

MONKEY-WRENCH.

SPECIFICATION forming part of Letters Patent No. 228,437, dated June 8,1880,

Application filed J one 11, 1879.

To all whom it may concern:

Be it known I, STEPHEN H. BELLOWs, of Athol, in the county of Worcesterand State of Massachusetts, have invented a certain new and usefulImprovement in MonkeyW/Vreiiches, of which the following is aspecification, reference being had to the accompanying drawings, where-Figure 1 is a side view. Fig. 2 is a front view. Fig. 3 is a view incentral vertical longitudinal section.

My invention is an improvement in that class of side'screw wrencheswhich commenced with the invention of Loring Goes, patented April 16,1841, wherein a screw located on one side of the wrench-bar is used tomove and adjust the movable jaw of the wrench. It is an improvement onthat subclass of said side-screw wrenches exemplified in the patent ofBenjamin F. J oslyn, dated July 10, 187 7 and numbered 192,920, whichsubclass not only embodies the Goes construction, but combines with itthe feature of connection and disconnection between the side screw andmovable jaw at will.

My invention consists in certain details of construction which involvecertain advantages hereinafter alluded to.

The letter a denotes the wrench-bar; b, the fixed jaw c, the step-platescrewing upon the wrench-bar and bearing the ferrule c; d, the woodenhandle, and cthe nut on the lower end of the wrench-bar, holding thewooden handle in place. v

The letter f denotes the movable jaw, sliding upon the bar andhavingabearing, f, for the adjusting-screw g, on the lower end of whichscrew is the rosette g, let into the bar, so that the screw restsagainst the side of the bar, this to prevent the screw from bendingunder severe back-thrust. A screw, h, driven up through the step-plate,forms a pivot for the lower end of the adjusting screw.

The movable jaw f bears in front the mortise i, in which lies, fits, andslides the half-nut meshing into the thread of the adjusting-screw. Thesides of the movable jaw bear the mortises k, and in them lie and slidethe nut-arms j j running backward and projecting from the back side ofthe movable jaw, their rear ends being joined by the tiepiece j, whichis riveted to the ends of the nut-arms. A spring, I, socketed in theback side of the movable jaw, presses the half-nut to mesh with theadjusting-screw. The user of the tool, by pressing with his thumb on thetie-piecej, unmeshes the nut from the adj usting-screw and moves themovable jaw to any desired adjustment, when, on removing said pressure,the spring returns the nut to mesh.

That part of this structure which is made up of the halfnutj, thearmsjj, and the tie-piece j is technically called the stirrup.

Now it will be noticed, on comparing my construction with theconstruction of said Joslyn wrench, that it (my construction) enables meto locate my stirrup, not, as in J oslyns case, be-

' low the lower extremity of the movable jaw,

but above such lower extremity, and in or on the body of the movablejaw.

The resulting practical advantages are obvious, to wit:

First, protection of the stirrup from accidental breakage or otherinjury. These wrenches are largely used in machine and other shops, andare not, as a rule, laid down gently, but are often thrown down rudely,and even in their legitimate and careful use are subject to hard hits.When this stirrup, which is the most delicate part of the wholemechanism, is below the lower end of the movable jaw it is in just theplace where it is most liable to accidental injury, and is entirelyunprotected therefrom. An adequate protection is afforded when thestirrup is located in and on the body of the movable jaw.

Second, in two wrenches of the same length (and all these wrenches gointo market by standard sizes) my construction admits of a much wideropening of the movable jaw than the Joslyn wrench. The wooden handle andthe jaw (the movable jaw) are fixed quantities as to length. A handlemust be of a certain length to afford an adequate grasp to the hand, andthe movable jaw must be of a certain length to resist the cookingtendency under strains. These lengths are well known and fixed towrench-makers. Just so much space as a stirrup below the movable jawtakes up on the bar, by just so much the opening capacity of the wrenchis diminished. My construction is not open to objection on this head.

screw g, the stirrupjjj, borne in and upon [0 the body of the movablejaw and above the lower end thereof, and the spring I, all substantiallyas shown and described.

STEPHEN H. BELLOWS.

Witnesses ALVIN HoUGH'roN, CHAR LES WADsWoRTH.

